Silver halide photographic light sensitive materials

Abstract

A silver halide photographic light-sensitive material containing, in at least one layer thereof, a compound capable of releasing a fogging agent upon an oxidation-reduction reaction with an oxidation product of a developing agent under an alkaline condition. The material has an increased sensitivity, an increased contrast and an accelerated development rate.

What is claimed is: 
     
       1. A silver halide photographic light-sensitive material which contains, in at least one layer thereof, a compound capable of releasing a fogging agent upon an oxidation-reduction reaction with an oxidation product of a developing agent under an alkaline condition during development processing, wherein said compound is a compound represented by the formula (I), (II), (III), (IV), (V) and (VI): ##STR32## wherein R 1 , R 2  and R 3 , which are the same or different, each represents a hydrogen atom, a halogen atom, an alkyl group, an aryl group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, a cyano group, an alkoxycarbonyl group, a carbomoyl group a sulfamoyl group, a carboxyl group, a sulfo group, a sulfonyl group, an acyl group, a cyano group, a carbonamido group, a sulfonamido group or a heterocyclic group; or R 1  and R 2  are bonded to each other to form a benzene ring or a 5- to 7-membered heterocyclic ring; R 4  represents an alkyl group, an aryl group, an acyl group, a carbomoyl group, a sulfonyl group or a sulfamoyl group; Z 1  and Z 2 , which are the same or different, each represents a hydrogen atom or a group capable of being removed by hydrolysis under an alkaline condition; X represents a group which exhibits a fogging effect in a developing solution when released; and Y represents a group which exhibits a fogging effect in a developing solution when released as Y--SO 2  NH 2  or its anion, wherein Y represents a reducing group, a group capable of action on a silver halide during development to form a developable silver sulfide center or a quaternary salt, wherein Y represents a group having the partial structure of hydrazine, hydrazide, hydrazone, hydroxylamine, polyamine, enamine, hydroquinone, catechol, p-aminophenol, o-aminophenol, aldehyde or acetylene, a group having the partial structure of thiourea, thioamide, thiocarbamate, dithiocarbamate, thiohydantoin or rhodanine, or a tetrazolium salt, wherein X has the formula (X):   (TIME).sub.m L.sub.1 (L.sub.2).sub.n A                     (X)     wherein TIME represents a timing group which releases --L 1  (L 2 ) n  A subsequently to the release of X, m represents 0 or 1; L 1  represents a group which is releasable for the release of X due to an oxidation-reduction reaction between compounds (I) and (IV) and a developing agent oxidation product under an alkaline condition when m is 0, or a group releasable from TIME of the released X when m is 1, wherein L 1  represents an aryloxy group, a heterocyclic oxy group, an arylthio group, a heterocyclic thio group or an azolyl group; L 2  represents a divalent linking group; n represents 0 or 1; and A represents a group which substantially exhibits a fogging effect to a silver halide emulsion when X exists in a developing solution in the form of X -  or X--H.   
     
     
       2. A silver halide photographic light-sensitive material as claimed in claim 1, wherein Z 1  and Z 2  each represents a hydrogen atom, an acyl group, a sulfonyl group, an alkoxycarbonyl group, a carbamoyl group, an oxalyl group or a group represented by the formula (VII), (VIII) or (IX): ##STR33## wherein R 5  represents an acyl group, a sulfonyl group, a cyano group, a carbamoyl group, a sulfamoyl group, an alkoxycarbonyl group, a nitro group, a carboxyl group, a sulfo group or an ammoniumyl group; and R 6  and R 7 , which may be the same or different, each represents a hydrogen atom, an alkyl group or the same groups as those enumerated for R 5  ; or R 5  and R 7  is bonded to each other to form a 5- to 7-membered ring; ##STR34## wherein R 8  represents a hydrogen atom, an alkyl group or an aryl group; V represents ##STR35## Q represents, when taken together with ##STR36## a non-metallic atomic group necessary to form a 5- or 6-membered ring. 
     
     
       3. A silver halide photographic light-sensitive material as claimed in claim 2, wherein Z 1  and Z 2  each represents an acetyl group, a chloroacetyl group,  a dichloroacetyl group, a trifluoroacetyl group, a benzoyl group, a p-nitrobenzoyl group, a methanesulfonyl group, a benzenesulfonyl group, a methoxycarbonyl group, a phenoxycarbonyl group, an ethylcarbamoyl group, a phenylcarbamoyl group, a pyruvoyl group, a methoxalyl group, a phenyloxamoyl group, or a group of the formula ##STR37## 
     
     
       4. A silver halide photographic light-sensitive material as claimed in claim 1, wherein L 1  represents a group of the formula ##STR38## wherein the mark * represents the bonding position to --TIME) m . 
     
     
       5. A silver halide photographic light-sensitive material as claimed in claim 1, wherein L 2  represents an alkylene group, an alkenylene group, an arylene group, a divalent heterocyclic group, --O--, --S--, an imino group, --COO--, --CONH--, --NHCONH--, --NHCOO--, --SO 2  NH--, --CO--, --SO 2  --, --SO--, --NHSO 2  NH-- or a combination thereof. 
     
     
       6. A silver halide photographic light-sensitive material as claimed in claim 1, wherein A represents a reducing group, a group capable of acting on a silver halide during development to form a developable silver sulfide center or a quaternary salt. 
     
     
       7. A silver halide photographic light-sensitive material as claimed in claim 6, wherein A represents a group having the partial structure of hydrazine, hydrazide, hydrazone, hydroxylamine, polyamine, enamine, hydroquinone, catechol, p-aminophenol, o-aminophenol, aldehyde or acetylene, a group having the partial structure of thiourea, thioamide, thiocarbamate, dithiocarbamate, thiohydantoin or rhodanine, or a tetrazolium salt. 
     
     
       8. A silver halide photographic light-sensitive material as claimed in claim 7, wherein A is a group represented by the formula (XI): ##STR39## wherein R 9  represents a hydrogen atom, an acyl group or an alkoxycarbonyl group; and R 10  represents an acyl group, a sulfonyl group, a carbamoyl group, an alkoxycarbonyl group, a sulfamoyl group, a thioacyl group, a thiocarbamoyl group or a heterocyclic group. 
     
     
       9. A silver halide photographic light-sensitive material as claimed in claim 1, wherein X is a group represented by the following formulae: ##STR40## 
     
     
       10. A silver halide photographic light-sensitive material as claimed in claim 1, wherein Y is a group represented by the formula (XI): ##STR41## wherein R 9  represents a hydrogen atom, an acyl group or an alkoxycarbonyl group; and R 10  represents an acyl group, a sulfonyl group, a carbamoyl group, an alkoxycarbonyl group, a sulfamoyl group, a thioacyl group, a thiocarbamoyl group or a heterocyclic group. 
     
     
       11. A silver halide photographic light-sensitive material as claimed in claim 1, wherein said compound is present in an amount of 10 -8  to 1 mol per mol of silver.